We know already that Mitsudomoe was green-lit to continue, but nonetheless the ep.13 bears marks of a season finale. It also stays true to itself to the very end... very, very end -- so that the punchline for the last joke is in the broadcast sponsor screen, which is going to be cut from media releases.
In some seasons I dropped every show half-way and had to grope around for replacements. Mitsudomoe struggled to the finish line, somehow. Now I wish it didn't, since its accomplishment puts next ranked contenders, Campanella and K-ON2, on back burner.
Seeing ep.10 (with chijo), Kurogane twittered "Mitsudomoe just keeps getting funnier and funnier by the episode. I'm glad it's getting a second season now." I don't know if I agree with the assessement (that gets funnier) and the conclusion (about the 2nd season). It seems to me the creators never transcended the source, and result was hit and miss. While they got better at processing the 4koma into anime with practice, the art quality took a slide from astonishing to mediocre. And since the show went nowhere, I got tired of it. The way its category dried up is an good indicator of perspectives of the 2nd season.
UPDATE: Moero Amazon says "来年早々の2期が今から待ち遠しいですよ", e.g. is looking forward to S2. Well, I'm glad someone does. She also has a stitch of bishojo Hitoha (low-res, naturally).
Also... I may sound a bit grumpy in this entry, Mitsudomoe stood where AsoIku and Ookami-san failed.
UPDATE: Aroduc says:
[] I’d consider Mitsudomoe a very disappointing show overall after an excellent first episode and a strong first half. Once we hit about episode 7 though, almost everything from then on turned sour. I think back to all the things that made me enjoy that episode, the visual style and parodies, the energy, the rapidfire and varied jokes, and all of that completely evaporated. Heck, they just completely dropped Hitoha being a pervert and always reading porn about three episodes into the series to totally rewrite her character for an endless parade of the exact same Gachi Ranger misunderstanding joke over and over again.
That ended up being my biggest problem with this series. Every now and then, a little variety and energy did seep back into the show, but nothing came even close to matching up to the first episode. All that creativity slowly withered away and was replaced by a calvacade of "person overhears part of a conversation, assumes that they’re talking about particularly nasty sadomasocistic sex." It stretches far past suspension of disbelief allows and undermines the joke by being utterly unbelievable. It really feels like they completely ran out of ideas for episodes 7-12 and simply picked on joke per segment to run into the ground.
Indeed the lack of creativity was noticeable. For example, in the final episode, Nipples switched his allegiance again. Haven't we been there before?
Still, I'm inclined to blame the formula of aimless parade of self-contained jokes with no development or story. It's like taking all the wrong lessons from Azumanga, and stepping on the same rake that Hidamari and GA fought so valiantly. The running out of material is simply inevitable here. If creators even watched Lucky Star, expect a major influx of new characters for the next season, or utter death and premature cancellation.